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i J.FISH." 1 Balanced Slide-Valves.

No. 224,525. Patented Feb. 17, I880.

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e/ LZ Z /f %zz4 MPEYERS. PHOTO-UTHOGRAPHER. WASHINGTON, D O.

ing the valve, and also itself, to any desired NITED- STATES,

PATENT OFFICE.

1 JOHN FISHLOF SUMMJI'LNEW JERSEY.

BALANCED SLI D'E-VALVE.

SIBEGIFIQATION" forming part ofLetters Patent No. 224,525,11ated February 1'7, 1880.

i Application filed Mayl9, 1679. i i

To all whom it may concern Be it known that I, JOHN in the county of Union and State of New Jersey, have invented certain Improvements in 1 Balanced Slide-Valves, of which the following theseat can be so adjusted as to operate as freely under full pressure as when thepressure is shut off entirely. At the same time the parts are so constructed as to effectually relieve the valve when the pressure in the cylinider becomes greater than the pressure in the a steam or air chest.

The first part of my invention relates to the application of a self-adjusting abutment-plate y for a slide valve, having ports D arranged for the admission and egress of steam or air.

These ports have each an area equal to half the areaofthecylinder-passage, and connect with fpassages E passing through the slide-valve to the cylinder-passage. The orifice of the passage in the abutment-plate is soformed in relation to its connecting-passage through the slide-valve that in all positions of the slide-valve in its travel there is always an i open communication from the cylinder-passage to the port in the abutment plate. I also attach pipes or connections 0 from each of the steam-ports in the abutment-plate, and also i from the exhaust-port toa chamberin the steam-chest cover. These are each packed by suitable packing to prevent the leakage of steam from the steam-chest to theinside of the j pipe. 'Eachpipe or passage and its connection to the steam-chest cover is separate en- .tirely from the other pipes. The aggregate 4 r y is so proportioned n relation to the area of outer area of these steam and exhaust pipes ;the ports in thecylinder-face that any desired i amount of pressure can be put on the back of the abutment-plate, so as to keep it tight on the slide-valve, and the same pressure keeps the slide-valve tight on the cylinder-face. It

i also allows the abutment-plate having the pressure of steam-chest on the back of it to follow up the wear of the valve. Thus the abutment-plate becomes the means of balanc- FISH, of Summit,

amount, and at the same time automatically follows up the wear of the valve and keeps it tight Without any attention or outside adjustment. Whatever pressure theremay be between the slide-valve and the piston at either end of. the stroke, these pressures have no influence on the valve, but each is transmitted through its own passagein the abutment-plate to the steanrchest cover. When the pressure by water or compression of steam in the passages exceeds the pressure in the steamchest the abutment-plate rises and relieves itself.

The second part of my invention relates to the slide-valve, which is formed in such a manner that the face next to the cylinder-face opens a port the area of which equals half the area of the cylinderpassage directly into the cylinder-passage. The opposite face of the valve opens aport in the abutment-plate, also half the area of the cylinder-passage, connectin g to suitable passages in the slide-valve that are always open to the cylinder-passage, By this arrangement, whatever pressure there may in the cylinder or its passages to the valve, the same pressure is maintained on the opposite faces of the valve, and keeps it in perfect balance in all positions of its travel.

In regard to the operation of exhausting the steam, the construction of thevalve is such that when the exhaust-edge of the valve has opened the induction-port one-half its Width the free opening of exhaust through the valve on both edges, top and bottom, equals the full area of cylinder-passage, or twice the area of the common slide-valve under the same conditions.

The accompanying drawings form a part of my specification, and represent the best means of carrying out my improvement in balanced slide-valves.

Figure 1 is a transverse section on the right through line A Aon plan, Fig. 3, and section B B, taken through line B B on plan, Fig. 3. Fig. 2 is a cross-section of cylinder-face, slidevalve,abutment-plate, and chest-cover. Fig. 3 is a plan of abutment-plate. Fig.4 is a'plan of cylinder-face ports. Fig. 5 is a plan of slide-valve.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. A self-adjustin g abutment-plate for a balanced slide-valve, having steam ports and passages opening into passages in the slide-valve in one direction and into separated chambers in the steam-chest cover in the other direction, the passages to steam-chest cover, the passages in abutment-plate and through the slidevalve being in open communication with the cylinder-passage in all -positions of the slide- "alve in its stroke, all constructed and arranged substantially as shown.

2. The balanced slide-valve, arranged so as to admit steam to the cylinder-passage on one face, in combination with the passages marked E E E E, passing through the valve, which allows the steam to pass to the cylinder-paspassages, substantially as described, and for the purpose herein set forth.

JOHN FISH. Witnesses WM. LITTELL, FRED. R. LITTELL. 

